1. Field of the Invention
The present invention relates to a token storage device for storing tokens such as gaming chips used in a casino or the like.
2. Description of the Background Art
Conventionally, in a casino or the like, in order to identify gaming chips, used are gaming chips, each of which has an IC tag for use in RFID embedded therein. By reading the IC tag for use in RFID, each of the gaming chips can be identified and managed. Therefore, in a casino table, antennas for reading IC tags for use in RFID are provided.
Furthermore, it is desired not only to manage the gaming chips placed on the casino table but also to manage the gaming chips in a state where the gaming chips are stored in a chip tray. Therefore, there may be a case where the chip tray has antennas embedded therein. Also in a case where the chip tray has the antennas embedded therein, as with the casino table, the antennas are provided in the vicinity of a plurality of gaming chips stored therein. Magnetic fields generated by the antennas penetrate through the gaming chips stored in the chip tray and develop electromotive force onto the IC tags for use in RFID. Thus, identification information of each of the gaming chips stored in the chip tray also can be detected (for example, refer to United State Patent Application Publication No. 2012/0080845 and United State Patent Application Publication No. 2013/0296041).
The range in which the magnetic field generated by an antenna covers is determined depending on a shape of the antenna and a strength of an electromagnetic wave outputted from the antenna. Therefore, if a distance between the IC tag for use in RFID and the antenna is longer than a predetermined distance in accordance with a sensitivity of the IC tag for use in RFID, the electromotive force to drive the IC tag for use in RFID comes not to be developed. Therefore, it is difficult to read out a variety of pieces of information such as identification information of the IC tag for use in RFID.
As described above, even if the distance between the IC tag for use in RFID and the antenna is long, by making a size of the antenna larger or making the strength of the electromagnetic wave outputted from the antenna stronger, a scope in which the magnetic field generated by the antenna covers can be expanded. Thus, it is made possible to read out the identification information and the like of the IC tag for use in RFID away from the antenna. However, a scope in which the magnetic field covers expands in each direction of three-dimensional x-y-z directions. Therefore, even if it is desired to read out identification information of only gaming chips in the first row stored in a chip tray, it is highly likely to read out identification information of gaming chips in rows in the vicinity of the gaming chips in the first row.
In addition, when in a chip tray in which IC tags for use in RFID are stored, reading of a plurality of antennas is conducted, assumed is a case where the same one IC tag for use in RFID is read out repeatedly by the plurality of antennas, thereby leading to a problem in that a reading speed may be reduced. Furthermore, when a multitude of IC tags for use in RFID are read out by one antenna, also assumed is a case where the multitude of IC tags for use in RFID simultaneously respond to a reading command of a reader, thereby leading to a problem in that IC tags for use in RFID in positions, for which reading-out is not desired, are read out and hence, a reading speed may be reduced.
Therefore, in view of the above-described problems, the present invention was made. An object of the present invention is to provide a token storage device which is capable of accurately reading out IC tags for use in RFID without increasing a magnitude of each of the magnetic fields generated by the antennas.